.TH std::cout,std::wcout 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::cout,std::wcout \- std::cout,std::wcout

.SH Synopsis
   Defined in header <iostream>
   extern std::ostream cout;    \fB(1)\fP
   extern std::wostream wcout;  \fB(2)\fP

   The global objects std::cout and std::wcout control output to a stream buffer of
   implementation-defined type (derived from std::streambuf), associated with the
   standard C output stream stdout.

   These objects are guaranteed to be initialized during or before the first time an
   object of type std::ios_base::Init is constructed and are available for use in the
   constructors and destructors of static objects with ordered initialization (as long
   as <iostream> is included before the object is defined).

   Unless std::ios_base::sync_with_stdio(false) has been issued, it is safe to
   concurrently access these objects from multiple threads for both formatted and
   unformatted output.

   By specification of std::cin, std::cin.tie() returns &std::cout. This means that any
   input operation on std::cin executes std::cout.flush() (via
   std::basic_istream::sentry's constructor). Similarly, std::wcin.tie() returns
   &std::wcout.

   By specification of std::cerr, std::cerr.tie() returns &std::cout. This means that
   any output operation on std::cerr executes std::cout.flush() (via
   std::basic_ostream::sentry's constructor). Similarly, std::wcerr.tie() returns
   &std::wcout. \fI(since C++11)\fP

.SH Notes

   The 'c' in the name refers to "character" (stroustrup.com FAQ); cout means
   "character output" and wcout means "wide character output".

   Because dynamic initialization of templated variables are unordered, it is not
   guaranteed that std::cout has been initialized to a usable state before the
   initialization of such variables begins, unless an object of type
   std::ios_base::Init has been constructed.

.SH Example


// Run this code

 #include <iostream>

 struct Foo
 {
     int n;
     Foo()
     {
         std::cout << "static constructor\\n";
     }
     ~Foo()
     {
         std::cout << "static destructor\\n";
     }
 };

 Foo f; // static object

 int main()
 {
     std::cout << "main function\\n";
 }

.SH Output:

 static constructor
 main function
 static destructor

.SH See also

   Init   initializes standard stream objects
          \fI(public member class of std::ios_base)\fP
   cerr   writes to the standard C error stream stderr, unbuffered
   wcerr  (global object)
   clog   writes to the standard C error stream stderr
   wclog  (global object)
   stdin  expression of type FILE* associated with the input stream
   stdout expression of type FILE* associated with the output stream
   stderr expression of type FILE* associated with the error output stream
          (macro constant)
